1. Field of the Invention
This invention relates to visual surveillance systems, and more particularly to a covert surveillance system which provides remote control of sophisticated camera functions such as zoom, focus, pan, tilt, etc.
2. Description of the Related Art
The purpose of a covert surveillance system is to monitor events from a remote or secret location. The equipment for this task ranges from simple television camera systems in banks or stores and metal-detecting devices at airports to airborne heat-sensing devices used by environmental officials to detect water polluters, and secret military satellites with a wide range of detection devices. The choice of surveillance system is dependent on the type of activity which must be monitored.
One of the most popular types of surveillance systems is the closed-circuit television. The closed-circuit television is used to watch banks, convenience stores, police stations, prisons, and other locations requiring constant security. Such systems have been installed in neighborhoods on an experimental basis to allow police departments to monitor high-crime-rate areas. Surveillance systems are in place in such diverse locations as the White House lawn, along portions of the U.S.-Mexican border, and in office buildings, amusement parks, and airports.
One of the problems in using closed-circuit televisions to monitor criminal activity is that the criminals are often aware that they are being watched. In locations such as banks, convenience stores, and prisons, notice of surveillance can often act as a deterrent to crime. However, if the purpose of the surveillance equipment is to capture criminal activity covertly (without tipping off the suspect), the camera for the surveillance system must be hidden.
Referring to FIG. 1, a prior art surveillance system 100 is shown which includes a camera 102 mounted to a motor 104 which rotates about a rod 106 suspended from a ceiling 108. The camera 102 is enclosed within an opaque globe 110 which hides the camera from view. The globe 110 has two lens portals 112 through which the camera 102 can view. In one embodiment, the camera 102 provides continuous video images to a remote monitor (not shown) via a coaxial cable. Other versions of the surveillance system 100 provide one way viewing globes 110 which allow the camera 102 to "see" through the globe at all rotations, while hiding the camera from external view.
While the surveillance system 100 "hides" the camera from external view, the presence of the surveillance system 100 is apparent. The globe 110 may be used to "hide" the momentary direction of the camera 102, or possibly to protect the camera from external vandalism, but its presence is not disguised. Thus, the surveillance system 100, while adequate to record activity within a particular location, is not useful for situations where the act of surveillance must be concealed.
A prior art surveillance system that is intended for covert monitoring is shown in FIG. 2. A periscope camera 200 is shown extending through a top surface 202 which is intended to be mounted on the roof of a vehicle, for example. The top of the camera 200 has a non-functional antenna 204 which is used to disguise the camera 200 as a cellular antenna, when the top of the camera 200 is flush with the surface 202. When in use, the camera 200 extends through the surface 202 and captures the desired images via a mirror 206. The captured images are transmitted to a lens and image capture device (not shown) within a box 208 which is mounted below the surface 202, and thus out of sight. The camera 200 is useful for instances where a van, or other type automobile, can be parked near the desired viewing area. However, when the vehicle itself would raise suspicion, the camera 200 does not provide an adequate solution.
Now referring to FIG. 3, an alternative prior art covert surveillance system 300 is shown. The surveillance system 300 includes a dummy electrical power line transformer 302 which is intended to be connected to a power line (not shown) on a power line pole. Within the transformer 302 is a surveillance camera 304 which views images through a window 306. The images are typically transmitted to a remote location for viewing and recording.
A problem associated with the surveillance system 300 is that it requires a power line technician to install it on a power line pole. This is often inconvenient, untimely, or expensive. In addition, the viewing window 306 is often observable by sophisticated suspects, thus defeating the covert purpose of the surveillance system. Furthermore, the viewing area of the camera 304 is restricted by the window 306, making the camera 304 useful in only one direction. And, the surveillance system 300 is useful only in those areas which have above ground power poles. In neighborhoods which have underground electric utilities, the surveillance system 300 is not applicable.
What is needed is a surveillance system which may be mounted in an undetectable location, which allows viewing in multiple directions, and which allows a user to remotely control sophisticated camera functions such as zoom, focus, aperture, pan and tilt. In addition, what is needed is a surveillance system which may be used in a variety of neighborhoods, parks, street corners, etc., without being noticed by sophisticated suspects.